ALXN1210 Versus Eculizumab in Adult Participants With Paroxysmal Nocturnal Hemoglobinuria (PNH) Currently Treated With Eculizumab

Inclusion Criteria:

Male or female ≥18 years of age.
Treated with eculizumab for PNH for at least 6 months prior to Day 1.
Lactate dehydrogenase level ≤1.5 times the upper limit of normal (ULN) at screening.
PNH diagnosis confirmed by documented by high-sensitivity flow cytometry.
Documented meningococcal vaccination not more than 3 years prior to, or at the time of, initiating study treatment.
Female participants of childbearing potential must use highly effective contraception starting at screening and continuing until at least 8 months after the last dose of ravulizumab.
Willing and able to give written informed consent and comply with study visit schedule.

Exclusion Criteria:

History of bone marrow transplantation.
Body weight <40 kilograms at screening.
History of or ongoing major cardiac, pulmonary, renal, endocrine, or hepatic disease that, in the opinion of the investigator or sponsor, would preclude participation.
Unstable medical conditions (for example, myocardial ischemia, active gastrointestinal bleeding, severe congestive heart failure, anticipated need for major surgery within 6 months of randomization, or coexisting chronic anemia unrelated to PNH).
Female participants who are pregnant, breastfeeding, or who have a positive pregnancy test at screening or Day 1.
Participation in another interventional clinical study or use of any experimental therapy within 30 days before initiation of study treatment on Day 1 in this study or within 5 half-lives of that investigational product, whichever is greater.